USP5 Promotes Ripretinib Resistance in Gastrointestinal Stromal Tumors by MDH2 Deubiquition

作者：Haoyu Sun, Zhiwei Cui, Chao Li, Zhishuang Gao, Jun Xu, Yibo Bian, Tianhao Gu, Jianan Zhang, Tengyun Li, Qianzheng Zhou, Dinghua Yang, Zhongyuan He, Bowen Li, Fengyuan Li, Zekuan Xu, Hao Xu · 发表于：Advanced Science · 年份：2024 · DOI：10.1002/advs.202401171 · 被引用次数：21 · 研究领域：Gastrointestinal Tumor Research and Treatment、Sarcoma Diagnosis and Treatment、Neurofibromatosis and Schwannoma Cases

Ripretinib, a broad-spectrum inhibitor of the KIT and PDGFRA receptor tyrosine kinases, is designated as a fourth-line treatment for gastrointestinal stromal tumor (GIST). It is tailored for patients resistant to imatinib, sunitinib, and regorafenib. As its increasing use, instances of resistance to ripretinib are becoming more frequent. Unfortunately, there are currently no scientifically mature treatment options available for patients resistant to ripretinib. Posttranslational modifications (PTMs) such as ubiquitination, in conjunction with its interplay with other modifications, play a collective role in regulating tumor initiation and progression. However, the specific association between ubiquitination and ripretinib resistance is not reported. Through proteome-ubiquitinome sequencing, increased levels of the USP5 protein and decreased ubiquitination in ripretinib-resistant GISTs are detected. Subsequent examination of the mass spectrometry findings validated the interaction through which TRIM21 governs USP5 expression via ubiquitination, and USP5 regulates MDH2 expression through deubiquitination, consequently fostering ripretinib resistance in GIST. Moreover, ZDHHC18 can palmitoylate MDH2, preventing its ubiquitination and further increasing its protein stability. The research underscores the correlation between posttranslational modifications, specifically ubiquitination, and drug resistance, emphasizing the potential of targeting the USP5-MDH2 axis to counteract ripr...